A speech signal picked up by a microphone can be corrupted by acoustic noise present in the environment surrounding the microphone as well as by certain system-introduced noise, such as noise introduced by quantization and channel interference. If no attempt is made to mitigate the impact of the noise, the corruption of the speech signal will result in a degradation of its perceived quality and intelligibility when played back to a listener. The corruption of the speech signal can also adversely impact the performance of speech coding and recognition algorithms.
One additional source of noise that can corrupt the speech signal picked up by the microphone is wind. Wind causes turbulence in air flow and, if this turbulence impacts the microphone, it can result in the microphone picking up sound referred to as “wind noise.” In general, wind noise is bursty in nature and can last from a few milliseconds up to a few hundred milliseconds or more. Because wind noise is impulsive and can exceed the nominal amplitude of the speech signal, the presence of such noise will degrade the perceived quality and intelligibility of the speech signal. Furthermore, because wind noise is non-stationary in nature, it is typically not attenuated by noise suppression schemes conventionally used to suppress acoustic noise or system-introduced noise.
Therefore, what is needed is a method and apparatus that can effectively detect and suppress wind noise.
The present invention will be described with reference to the accompanying drawings. The drawing in which an element first appears is typically indicated by the leftmost digit(s) in the corresponding reference number.